Solve for $x$ and $y$ using substitution. ${-2x-6y = 0}$ ${y = x+4}$
Solution: Since $y$ has already been solved for, substitute $x+4$ for $y$ in the first equation. ${-2x - 6}{(x+4)}{= 0}$ Simplify and solve for $x$ $-2x-6x - 24 = 0$ $-8x-24 = 0$ $-8x-24{+24} = 0{+24}$ $-8x = 24$ $\dfrac{-8x}{{-8}} = \dfrac{24}{{-8}}$ ${x = -3}$ Now that you know ${x = -3}$ , plug it back into $\thinspace {y = x+4}\thinspace$ to find $y$ ${y = }{(-3)}{ + 4}$ $y = 1$ You can also plug ${x = -3}$ into $\thinspace {-2x-6y = 0}\thinspace$ and get the same answer for $y$ : ${-2}{(-3)}{ - 6y = 0}$ ${y = 1}$